World War II ke baad, Australia ke abaadi has more than doubled, spurred by large-scale European immigration during the immediate post-war decades. Non-European immigration, mostly from Asia and the Middle East, has increased significantly since the 1970s; due in large part to the abolition of the White Australia Policy.

In the 2006 Australian Census [3] residents could nominate up to two ethnic groups to define their ancestry. Proportionate to the Australian resident abaadi, the most commonly nominated ancestries were:

The category of "No Religion" includes non-theistic beliefs such as humanism, atheism, agnosticism and rationalism. A fifth sub-category is "No Religion - nfd" ("nfd" = no further definition). The Australian Bureau of Statistics does not provide statistics on how many people belong in each sub-category on "No Religion".

The Australian Bureau of Statistics 2001 Census Dictionary statement on religious affiliation states the purpose for gathering such information:

Data on religious affiliation are used for such purposes as planning educational facilities, aged persons' care and other social services provided by religion-based organisations; the location of church buildings; the assigning of chaplains to hospitals, prisons, armed services and universities; the allocation of time on public radio and other media; and sociological research.

As in many Western countries, the level of active participation in church worship is much lower than would be indicated by the proportion of Christians indicated in the ABS statistics; weekly attendance at church services is about 1.5 million, about 7.5% of the abaadi.[16]